Volume and Shape of the Caudate Nucleus and Putamen as Biomarkers for Parkinson's Disease Progression

Parkinson’s disease is a degenerative disorder of the central nervous system. Symptoms include shaking, muscle stiffness, speech problems, memory loss and vision problems. The disease involves the inactivation of dopamine-producing cells in a part of the brain called the substantia nigra. There is no definitive test to diagnose Parkinson’s disease, making it difficult to diagnose in its early stages. By the time a patient is diagnosed, up to 80 per cent of the dopamine-producing cells may have already stopped working. There is therefore a need for a more reliable test for diagnosis of Parkinson’s disease. There is reason to believe that Parkinson’s disease can be detected by measuring the size and shape of two anatomic structures within the brain that are both connected to the substantia nigra: the caudate nuclei and the putamen. When the cells in the substantia nigra become inactive, less dopamine is sent to the caudate nuclei and putamen. Aaron Ward is studying whether a decrease in dopamine results in changes to the size or shape of the caudate nuclei or putamen. Using magnetic resonance imaging, Ward is computing a 3-D representation for each patient’s caudate nuclei and putamen. The ultimate goal is to discover aspects of the shape of these structures that could serve as indicators of Parkinson’s disease. This would allow earlier and more reliable diagnosis, and facilitate the tracking of patient response to therapy.